Plate type heat exchanger



Unite States atent [72] Inventor [21 App]. No. [22] Filed [45 Patented [7 3 Assignee Frederick A. Lockcl, Milwaukee. Wis. 740,524

June 27, 1968 Oct. 6, 1970 Aqua-Chem, Inc.,

a corporation of Wisconsin [54] PLATE TYPE HEAT EXCHANGER 0 ;7 f2 4 5 5 6/2 22 Qn@ 2,865,613 12/1958 Egenwall 3,228,465 1/1966 Vadot Primary Examiner-Robert A. OLeary Assistant Examiner-Theophil W. Streule Attarney-Hofgren, Wegner, Allen, Stellman & McCord ABSTRACT: A heat exchanger is manufactured by fastening together a plurality of specially designed pressed or stamped sheet metal plates. Each plate has high heat transmission characteristics and has ribs, indents and corrugations which are adapted to cooperate with appropriately placed ribs, indents and corrugations on adjacent plates and to cooperate with sealing strips or gaskets interposed between adjacent plates whereby the sealing strips are completely supported against blowing out while the ribs and channels maintain prescribed passageways for flow of fluids between the plates in the heat exchanger.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to heat exchangers and more particu larly to improved plates for a plate type heat exchanger.

2. Description of the Prior Art Plate type type heat exchangers have been widely known and used for many years. The heat exchangers consist of several layers or levels of plates which are bolted together with appropriately positioned gaskets or sealing strips such that two or more fluids admitted to separate inlets to the heat exchanger pass through the tortuous paths created by the ribs, channels and corrugations on the juxtaposed plates. Many various designs have been proposed for preventing the gaskets from being excessively crushed by providing supporting elements in one plate cooperating with parts of the next adjacent plate but the result has been to blow the gaskets out by the relatively high pressures of the fluids passing through the heat exchangers. In addition, leakage past the gaskets also resulted from the lack of sufficient sealing pressure on the gaskets occasioned by the supporting elements between the plates preventing the plates from coming together enough to create the necessary seal.

Some of the attempts to solve the problems are shown in the Astle U.S. Pat. No. 2,203,123; Seligman et al. U.S. Pat. No. 2,217,567 Ljungstrom U.S. Pat. No. 2,787,446 and Egenwall et al. U.S. Pat. No. 2,865,6l 3. In Astle and Seligman et al. specially shaped grooves and specially designed and reinforced gaskets were proposed. Ljungstrom shows channels formed in two different directions from a plane, but does not provide for supporting the gaskets et al. Egenwall et al. provides cooperating projections and planar surfaces spaced apart and on alternating sides of the gasket to attempt to back the gasket. All of these prior art devices fail to teach a complete solution to the sealing and gasket backing problem.

SUMMARY OF THE INVENTION The invention is directed in brief to the provision of newly designed heat exchanger plate which can be produced by stamping or rolling and which has ribs, indents and corrugations adapted to cooperate with appropriate surfaces on adjoining plates to provide predetermined flow paths when the plates are stacked and bolted together. Each plate has a con tinuous one-sided indentation around the outer regions of the plate which provides a continuous backing support for a gasket or sealing strip positioned in the indentation and held therein by an adjoining plate. In addition, supporting lugs or projections are formed in spaced relationship to each other and to the one-sided indentation for holding the outer edge portions of adjacent plates in predetermined supported relationship. The orientation of the respective ribs of the plates is such as to increase the agitation and heat transfer relationship of the resulting heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of my improved heat exchange plate;

FIG. 2 is a top view of a heat exchanger in assembled form;

FIG. 3 is a side view of the heat exchanger of FIG. 1;

FIG. 4 is a plan view of one plate of the heat exchanger with the gasket in one particular position thereon;

FIGS. 5 and 6 are plan views similar to FIG. 4 with the gasket in different locations thereon;

FIG. 7 is a cross-sectional view taken on the line 7-7 of FIG.

FIG. 8 is a cross-sectional view taken on line 88 of FIG. 1; FIG. 9 is a cross-sectional view taken on line 9-9 of FIG.1;

FIG. 10 is a cross-sectional view taken on line 10-10 of FIG. 1 showing several adjacent plates stacked together with gaskets therebetween;

FIG. 11 is a cross-sectional view taken on line I1-l1 of FIG.

FIG. 12 is a cross-sectional view taken on line 12-12 of F [6.1;

FIG. 13 is a cross-sectional view taken on line 13-13 of FIG.

FIG. 14 is a cross-sectional view taken on line 14-14 of FIG. 1.

DESCRIPTION OF THE PREFERRED FORM OF MY INVENTION Referring to the drawings in detail, the structure shown is a plate type heat exchanger 10 which has a plurality of heat exchange plates 12 stacked together in a predetermined relationship with appropriated gaskets or sealing elements 14 compressed between each plate 12. The stack of plates and gaskets are secured between appropriate end plates 16 by means of rods or bolts 18 in a conventional manner.

Each heat exchange plate 12 as shown best in FIG. 1 may be formed of a flat sheet of material preferably metal, such as stainless steel, aluminum or copper-nickel alloy which is rolled, pressed or stamped so as to emboss predetermined corrugations and configurations into the sheet to form the heat exchange plate. Specifically the flat sheet of material has a planar surface 20 on one side thereof and has the corrugations and configurations formed in one direction away from said planar surface. Several openings are out through the plate 12 such as the six openings illustrated as 22, 23, 24, 25, 26 and 27, which openings have their surrounding walls 29 formed downwardly and inwardly as shown in FIG. 13 with the bottom surface 30 lying in a plane parallel to and spaced from the planar surface 20 thereof. The planar surface 20 surrounding the outer regions of each opening, i.e. 22, 23, 24, 25, 26 and 27, has a plurality of depressions 32 formed downwardly therefrom to produce an appearance of scalloping therearound. The bottom surfaces 34 of said depressions 32 lie in the plane coextensive with the plane of the bottom surface 30 which bottom surfaces 34 extend around the scallop ing of each opening and are adopted to receive a gasket or sealing element 14, when appropriate, as will be discussed hereinafter.

Between the gasket receiving depressions of bottom surface 34 and the principle central portion 36 of the plate 12 is formed several groups of raised support members 38 as shown in FIGS. 1, 11 and 12 which members are spaced laterally from each other and from the embossments in said central portion 36 of said plate. The support members 38 have relatively squared off top surfaces 40 lying in the plane of said planar surface 20 and have walls 42 joining said surfaces 40 with the surfaces 44 lying in the plane: of the bottom surface 30.

The principle central portion 36 of the plate 12 has plural parallel corrugations 46 embossed therein with approximately one-half48 of said corrugations being angularly disposed from one direction with respect to the longitudinal center line of said plate and approximately the other half 50 of said corrugations being disposed at the same angle but from the opposite side of said center line of the plate so as to produce an offset V pattern there in. That is, the corrugations 46 of group 48 on the lower side of plate 12 as shown in FIG. 1 meet the central rib 52 at an angle to the center line of said rib. The corrugations 46 of the group 50 on the upper side of plate 12 as shown in FIG. 1 meet the center line of the rib 52 at substantially the same angle but the whole group 50 of corrugations 46 is displaced one corrugation to the right (as viewed in FIG. 1). That is, the end of a trough 54 of a corrugation 46 from group 50 will line up with and be spaced from the raised crest 56 between two troughs S4 of corrugations 46 in group 48. The outer ends of the corrugations 46 in groups 48 and 50 terminate in an indentation 58 around the periphery of said central portion 36 of the plate. The reason for the particular alignments of the corrugations 46 will become apparent hereinafter.

Around the outer peripheral portion 59 of the plate 12, the planar surface 20 extends from the edge of the plate inward to some extent. Each plate 12 has a pair of cut out circular shaped apertures 60, 62 which are formed in the opposite end portions 64, 66 of the plate 12 in the same locations relative to the corners of the plate on opposite ends of a diagonal drawn across the plate. The apertures 60, 62 are located in such a way that the plates in a stack cannot be installed upside down and provide for rotating every other plate I80 in the plane of the plate relative to the next adjacent plate as will be explained more fully hereinafter.

A plurality of embossments or projections 68 are formed downward from the planar surface in the peripheral portion 59 of the plate 12. Each projection 68 is formed with a wall 70 and a bottom surface 72 which bottom surface lies in the plane of the bottom surface 30. The projections 68 are spaced from each other about the periphery of the plate except that at the two end portions 64, 66 they are spaced from and follow the general contour of the scalloping around the openings 2227. The locations of the projections 68 along the top edge portion 59 of the plate with respect to the locations of the projections 68 along the bottom edge portion of the plate as viewed in FIG. I are such that when one plate 12 is rotated 180 in the plane of the plate relative to an adjoining plate 12 the bottom surface 72 ofthe projections 68 will align with the planar surface 20 between adjacent projections 68 so as to form supports between said adjoining plates.

Spaced inwardly toward the central portion 36 of the plate 12 from the projections 68 is formed another embossment or elongate indentation 58 which has a generally vertical wall 74 extending from the planar surface 20 to a bottom surface 76 which bottom surface lies in the same plane as said planar surface 30. The elongate indentation 58 extends continuously around the outer periphery of said plate and is spaced inwardly from said projections 68 and is shaped to receive the gasket or sealing member 14. The wall 74 of the indentation 58 is continuous and extends completely around the general periphery of the plate and forms a continuous backing member for the gasket outwardly thereof whenever said gasket lies in said indentation. The bottom surface 76 of the elongate indentation 58 joins with the bottom surfaces 34 of the scallops 32, with the walls 42 of the raised portions 38 and with the crests 56 and troughs 54 of the corrugations 46.

In manufacturing a heat exchanger 10, for example, each plate 12 is given a designation such as A (FIG. 4), B (FIG. 5) and C (FIG. 6) which determines the arrangement of the gaskets or sealing members 14 with respect to the openings 2227. Plate A of FIG. 4 has the gasket 14 positioned as by cementing in the elongate indentation 58 such that it extends along the side periphery of the plate, around the outside of openings 27 and in the indentation or channel 58 between openings 27 and 26, along the indentations 58 between the raised portions 38, along the other side periphery, around the opening 24, in the indentation 58 between openings 24 and 23, and along the indentations between the raised portions 38 to rejoin the peripheral edge indentation 58. The gasket 14 on a plate A as shown in FIG. 4 connects the openings 24 and 27 across the top corrugated surface of the plate. In this way fluids flowing in or out of openings 24, 27 will be in flow and heat transfer communication with the corrugations 46 in the plate within the confines of the gasket 14 on the top surface of the plate A. Likewise plates 8 and C have gaskets 14 which provide for communication between openings 23, 26 and 22, 25, respectively. Individual ring gaskets l4'are placed in the indentations 58 around the remaining openings in the plate so as to provide flow of fluid past the corrugations on that side of that plate. that is gaskets 14' are positioned around openings 25, 26, 23, 22 in plate A to provide flow from the plates above and below bypassing the corrugations on the top surface of plate A. The same is true with respect to plates B and C.

An end plate or cover 16 has nozzles 80 and nozzle gaskets (not shown) cemented or secured in place in the openings therein. An appropriate predetermined stacking pattern of the plates A, B and C is selected such that every other plate in the stack is rotated I80 in the plane of the plate relative to its adjoining plate. When the stacking has been completed another end plate 16 with nozzles 82 and nozzle gaskets (not shown) secured in the openings therein is placed on the stack and the bolt or rods 18 are drawn up evenly. When the rods 18 are properly tightened the gaskets will be compressed as shown in FIG. 10 and the bottom surfaces 72 of the projections 68 (see plate A FIG. 10) will bear against the planar surface 20 of the next adjacent plate B. The contact of the projection 68 of plate A with the planar surface 20 of plate B will be between adjacent projections 68 on plate B formed in said planar surface 20 and the projections 68 on plate B will bear on the planar surface 20 of the plate C between projections formed in said planar surface 20 of said plate C.

The continuous indentation 58 having the continuous backing wall 74 outwardly thereof provides a positive retaining support for the gaskets or sealing members 14 so as to prevent blowouts or leaking between adjacent plates. In addition, the projections 68 spaced apart from each other and spaced outwardly from the continuous indentation 58 provides a means for preventing excessive compressing of the gaskets or sealing members 14 and still permits sufficient compression of said gaskets 14 to seal against the plate and prevent blowouts of said gaskets. The combined action of the spaced projections 68 and the continuous indentation 58 for the gasket 14 produces a substantially trouble-free seal and gasket support structure.

The corrugations 46 in the central portion 36 of each plate 12 are specially oriented relative to each other and to the surrounding embossments that when one plate is rotated 180 and is stacked on top of the next plate the angled corrugations 46 of one plate cross the corrugations 46 of the next plate with the crests 56 of the corrugations of one plate in contact with the bottom of the troughs 54 of the corrugations of the plate next to it so as to form a continuous and tortuous path therethrough. That is, fluid flowing from one opening (i.e. 27) will flow through the undulating pattern of up one corrugation over the crest and down into the trough therebetween and so on until it reaches the other opening (i.e. 24). The tortuous path will create considerable turbulence such that the maximum amount of heat will either be absorbed by the fluid or given up by the fluid to the plates and to the out of contact fluid on the other side of said plate. The misalignment along the rib S2 of the ends of the crests 56 and troughs 54 of one group of corrugations 48 with the troughs 54 and crests 56 in the other group of corrugations 50 of each plate will further contribute to breaking up the flow patterns of fluids over the plates so as to accomplish maximum mixing within the fluid and consequently maximum heat transfer.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitation should be understood therefrom, as some modifications may be obvious to those skilled in the art.

lclaim:

1. A heat transmission plate assembly having a plurality of stacked plates, each of said plates having a planar surface with means extending from one side of each of said plates, at least one of said means comprising an elongate indentation from said planar surface along an outer peripheral edge of said plate, said elongate indentation having at least one continuous wall along the outermost side thereof, others of said means being formed in the midportion of each plate as offset corrugations, and at least several more of said means comprising projections spaced apart from each other and spaced outwardly and substantially equidistantly from said continuous wall by a planar portion extending from said elongate indentation, said projections are positioned around the edge portion of the plate such that rotation of one plate in its plane l from an adjacent plate will position the projections on said one plate against planar surfaces between adjacent projections on said adjacent plate.

2. In heat exchanger having a plurality of heat transmission plates having offset corrugations in a general V-shaped pattern and secured together in stacked, spaced apart relationship with gasket members positioned between adjacent plates, each of said plates having a planar surface with portions thereof pressed into protruding means from one side of said planar surface relative to said plate, at least one of said protruding means comprising in combination a continuous indentation from said planar surface around the outer periphery of said plate so as to define a continuous wall extending from said one side of said planar surface, a bottom wall extending from said wall in a plane substantially parallel to said planar surface and displaced laterally therefrom, and a plurality of individual ones of said protruding means being spaced apart from each other and spaced outwardly from said continuous wall to form spacer members between adjacent heat exchanger plates.

3. A heat exchanger as claimed in claim 2 wherein one of said gasket means is disposed in said continuous indentation, and said plurality of individual protruding means is oriented around said edge portion of the plate such that rotation of one plate in the plane of said plate relative to its adjacent plate will position the protruding surfaces of the protruding means on one plate against planar surfaces between adjacent protruding means on said adjacent plate.

4. A heat exchanger as claimed in claim 3 and having means for securing said plurality of plates together to compress the gaskets until said plurality of individual ones of said protruding means engage adjacent plates whereby the continuous wall of the continuous indentation serves as a continuous backing means for said gasket.

5. A heat exchanger as claimed in claim 4 wherein the central portion of the heat exchange plate having the corrugations of general V-shaped pattern with the corrugations on one side of the V offset at the center so as to misalign the ends of one side from the ends of the other side. 

